Sewing-machine presser-foot mechanism



A ril 17, 1951 J. M. WASHBURN 2,549,259

SEWING MACHINE PRESSER-FOOT MECJHANISM Filed Feb. 14, 1950 Inventor: JoknMWashburn Patented Apr. 17, 1951 SEWING-MACHINE PRESSER-FOOT MECHANISM John M. Washburn, West Hartford, Conn., assignor to The Merrow Machine Company, Hartford, Conn., a corporation of Connecticut Application February 14, 1950, Serial No. 144,061

8 Claims. (01. 112-235) This invention relates to sewing machine presser-foot mechanism and more particularly to a stop for use with a presser-foot of the type commonly known as center-hinged for the reason that the foot proper has a pivotal connection, at or near its fore and aft center, with its sup porting arm to permit of tilting the foot relative to a cooperating work support or needle plate. A rocking movement of the presser-foot permitted by its hinged relation to the arm enables the bearing surface of the foot to better engage and ease passage thereunder of irregularities in the thickness of work engaged thereby. When an extra thickness of work such as a cross seam is, by feeding means, advanced across the length of the foot, first the toe and then the heel of the foot is elevated relative to the needle plate. Beyond certain limits, elevation of the heel of the foot is objectionable, and the object of this invention is to provide means whereby the range of movement of the heel of a center hinged presser-foot away from the needle plate may be held to a definite limit which may be varied to suit in this respect especial requirements of different types of material comprising the work.

Withthis and other objects in view one feature of the invention resides in the arrangement of a stop interposed between opposed surfaces of the presser arm and heel of the foot and adjustable to different positions along those surfaces. Another feature of the invention resides in the relative inclination of the opposed surfaces on the presser arm and heel of the foot to provide a wedge shaped gap in which the stop is interposed and along which it may be adjusted to choose the limit of movement of the heel of the center-hinged presser-foot.

In the accompanying drawings.

Figure 1 is an end view of part of a sewing machine including therewith presser-foot mech anism embodying my invention in its preferred form.

Figure 2 is a plan view of the presser-foot and associated parts shown in Fig. 1 together with part of the arm to which the presser-foot is hinged.

Figure 3 is a side view of assembled parts shown in Fig. 2.

Figure 4 is a perspective view of the free end of a presser arm.

Figure 5 is a sectional view on line 5-5 of Fig. 1.

In accordance with the preferred form of the invention, a stop is slidably adjustable to different selected positions along opposed surfaces of the presser-footarm and the presserfoot where it is secured to limit pivotal movement of the presser-foot. To form a wedge shaped gap the opposed surfaces are inclined relative to each other in a direction normal to: the axis of the pivot for the presser-foot. At. one end of the stop, a shank extends along a.

lateral side of the presser-foot arm, which shank.

is provided with an elongated slot arranged. parallel to the inclined surface of the arm so a.

bolt through the slot permits the stop to slide.-

along the gap to a selected position where it. may be secured by tightening the bolt.

Referring to the drawings, the sewing machineillustrated includes frame I, head 2, work plate. 3, needle plate 4 and a rocker 5, the latter being fulcrumed on a shaft 6. Pivoted on rocker 5, as at I, for lateral swinging movement, is a pres--- ser-arm 8, engageable when in its normal operating position by presser-bar 9, the latter ter-- minating in a bifurcated head 9 which strad dles arm 8 at the arcuate seat 8. Presser-bar- 9 is urged toward the presser-arm by a spring l0 housed within the tubular head 2 and op-- posed by a nut II which provides for adjustment to vary tension of spring III. For releasing the presser-bar 9 from engagement with arm: 8, a latch 12 is slidably mounted on the head, When arm 8 is thus disengaged, it may be swung: laterally from its normal position to provide con-- venient accessibility thereto and to various other parts. From the free end of arm 8 a stud l5 projects at right angles to the adjacent face of the arm and at right angles to the direction of the feed of the machine when the arm is in operative position. The stud I5 may be termed an axial stud, inasmuch as it provides a support: upon which a presser-foot I6 is secured for rock-- ing or tilting movement thereon. An arm shaped substantially as shown and described is: especially desirable when the foot is carried at the end of'a pivotal element such as the arm.

8 but it will be understood that when the footis otherwise supported, as for example by a vertically movable bar, the equivalent of arm 8 may be constructed to meet required conditions and to properly'position the stud l5 for support of presser-foot l5. As shown the presser-foot, approximately midway of its length, is preferably increased somewhat in thickness as at H, and across its upper face at right angles to its length is extended a channel [8 which forms a bearing to receive the lower edge of arm stud I15 which is semicircular in cross-section. The channel or bearing I8 is similarly shaped .in cross-section but is of somewhat less depth than the radius of the lower edge of the stud [5 in order that the foot may rock upon the stud as indicated. The edge of the stud opposite the semicircular edge is slightly rounded for a purpose that will presently appear. As commonly applied to a presser-foot of the type shown, are a stitch finger 19, secured by ascrew 20, and an uncurling block 2 I, secured by a screw 22.. Means for holding p'resser-foot IE to arm 8 with a yieldable pressure comprises a flat spring 23 which is held in place by screw 20, above mentioned, with the resilient arm 24bearing upon stud 15, the latter being held snugly in its seat in channel I8, but not so tightly clamped as to prevent rocking or tilting of the foot upon the stud. To prevent side play of the footrelatively to the arm, stud l'is provided with a head 25 to thereby form a confining channel to receive therein the spring arm 24.

The presser-foot mechanism thus far described is similar to that disclosed in United States Letters Patent No. 1,002,380, granted September 5, 1911, upon application of William H. Stedman. The present invention as already stated is directed to-an adjustable stop whereby the range of movement of the heel of a hinged presser-foot away from the needle plate or work support may be held to a definite limit, which limit may be varied to suit different requirements. For this purpose a stop 26, is mounted to the rear of stud l5,-o'n arm' 8, where the latter has a flat side 21 substantially normal to the plane of the fiat surface 28 on the heel of the presser-foot, and a flat edge surface 28 opposed to said fiat surface 28 and over the heelof the foot. As illustrated in Fig. 3, flat surfaces 23 and 28' are relatively inclined so they diverge rearwardly from thestud E5 to form a wedge shaped gap between the presser-foot arm 8 and the presserfoot it. Stop 25 is, slidable on 'flat surface 28 to different selected positions in the gap. Extended at right angles to, and from one side of stop 26, is a shank ffi having an elongated slot 3Gtherein to receivea screw 3| which is threaded into arm 8. at 32. Slottfi is formed substantially parallel to flat edge surface 28 so stop 26 slides varied to suit requirements; Bytighteningscrew 3| inthe elongated slot 39,, shank 29 and stop 26 may be secured'in any desired position along the inclined .edge surface 28 of arm 8.- Any turning of stop 26 about the axis of its securing stop a flat surface of ample extent for contact with the opposed surface 23 of arm 8.

In Fig. 1 stop 26 is shown at the extreme for! ward. end of its range of adjustment andin this position it limits movement of the presser-foot heel toward the opposed surface of arm 8 to the maximum amount available, or in other words,

shaped gap therebetween, and a stop within said.

gap and slidably adjustable on one of said membersalong said surface thereof in the direction I of inclination of said surfaces to different posi tions in said gap. r 3. A sewing machine presser-foot mechanism comprising a presser-foot-arin member, a presser foot member pivotally connected to said arm member, said members having opposed surfaces relatively inclined in a direction normal to the axis of said pivotal connection, .anda stop intere posed between saidsurfaces and slidably ad-juste able along said surface thereof in said direction.

4. --A sewing machine .presser foot mechanism comprising -.a presser-foot arm, a presser-rfoot pivotallyconnected to said arm, said arm and presser-foothaving opposed surfaces movableto+ ward each other, anda stop interposed between said surfaces and slidably adjustable-alongsaid surface on said arm. I l I a 5. A sewing machinepresserefoot mechanism comprising a presser-foot arm, a .presser-foot pivotally connected to said arm, saidarmsand presser -foot having relatively inclined opposed surfaces forming a wedge shaped gap therebetween, and a stop-within saidgap slidably adjust,-

pivotally connected to said arm, said arm .and

screw 31 would beobjectionablebut any tendency ingthis respect is overcome'by making-on the pivotally connected to-said arm, said presser-foot having a fiatsurfaca said-arm having anopposed flat surface inclined relativev to said surface on said presser-foot, a. stop slidable along saidiopposediiat'surface on saidarm, and meanssecure ing said stop on said arm with said stop. in differ.-

the toe of the foot is prevented from tilting downwardly more than the amount indicated in this view. Obviously this amount may be reduced as desired by adjustingstop Ziircarwardly.

As-is apparent from the foregoing description, stop Zois easily adjustable-to anydesired position witha minimum effort and in a very 'short time. The operator need only loosen screw 3|, slide the stop to the desired position and'then tighten the screw. This adjustment is'facilitated .bythe arrangement of screw'3i on the side of the presser-footarm-where thescrew is readily accessibleand easily turned. r

ent selected positions along said opposed surfaces.

.8. A sewing machine presser-foot mechanism comprising a presser -foot havingafiat surface, a presser-foot arm having a flatsurface, means pivotally connecting said presser-foot on said arm with said fiatsurfaces opposed and-inclined rel ative to eachother, a stop slidable a-long' said 'fla-t 7 surface on said-arm, a shank on said stopext'ending along a lateral side of said-wall, said shank being formedwith an elongated slot parallel-to said fiat surface on said arm, and means in said slot slidab'ly supporting said shank and stop on said arm for securing said shank to said'lateral surface with said stop in different selected posi: tions along said surface.

.J 'WASHBURN.

No references cited. 7 

